Causes of Skin Lumps

Insect Bites. The most common cause of an itchy bump is a mosquito bite. Other insects can also cause little bumps.

Stings. A bee sting can cause a painful bump. The swelling can become quite large.

Lymph Nodes. Most common cause of a lump or mass felt under the skin. Commonly found in the neck or groin. Nodes have a boundary or edge and are movable. This is not the case for the swelling seen with insect bites. Lymph nodes become larger with infections.

Scalp Hematoma. The most common cause of a lump on the head is a scalp hematoma (goose egg). In a child under 2 years of age the injury may not have been seen.

Injuries. New lumps anywhere can be caused by an injury that wasn't observed. A bruise is often present with the swelling.

Callus. Broken bones heal with new bone formation. The medical term is callus. The callus feels like a bony knot that is larger than the bone itself. A callus is most commonly felt after a collarbone fracture.

Boils. A boil is a skin abscess. It causes a very painful red lump.

Lumps that are a Normal Part of the Body

Breast Bud. A small disc-shaped lump felt under the nipple. It indicates the onset of puberty in 7-12 year old girls.

External Occipital Protuberance. The bony lump felt at the base of the skull in back.

Mastoid Process. The bony lump felt behind each lower ear.

Xiphoid Process. A small hard lump felt at the lower end of the sternum (breastbone).

Common Objects Used to Guess the Size

Pea or pencil eraser: ¼ inch or 6 mm

Dime: ¾ inch or 1.8 cm

Quarter: 1 inch or 2.5 cm

Golf ball: 1 ½ inches or 3.8 cm

Tennis Ball: 2 ½ inches or 6.4 cm

When to Call for Skin Lump

When to Call for Skin Lump

Call Doctor or Seek Care Now

Redness spreading from the lump with fever

Groin swelling and painful

Age less than 12 months and on scalp. Exception: normal bump in back at base of skull.

Your child looks or acts very sick

You think your child needs to be seen, and the problem is urgent

Contact Doctor Within 24 Hours

Redness spreading from the lump without fever

Boil suspected (painful, non-itchy, red lump)

Age 12 months or older and on scalp. Exception: normal bump in back at base of skull.

Can't move nearest joint normally (bend and straighten completely)

Swelling is painful and cause not known

You think your child needs to be seen, but the problem is not urgent

Contact Doctor During Office Hours

Large lump more than 1 inch (2.5 cm) and cause not known

Small lump lasts more than 7 days and cause not known

You have other questions or concerns

Self Care at Home

Small lump present 7 days or less and cause not known. Reason: probably due to insect bite not observed.

Breast bud - normal lump under the nipple

External occipital protuberance - normal lump on back of head

Mastoid process - normal lump behind each lower ear

Xiphoid process - normal lump at bottom of breastbone

Call Doctor or Seek Care Now

Redness spreading from the lump with fever

Groin swelling and painful

Age less than 12 months and on scalp. Exception: normal bump in back at base of skull.

Your child looks or acts very sick

You think your child needs to be seen, and the problem is urgent

Contact Doctor Within 24 Hours

Redness spreading from the lump without fever

Boil suspected (painful, non-itchy, red lump)

Age 12 months or older and on scalp. Exception: normal bump in back at base of skull.

Can't move nearest joint normally (bend and straighten completely)

Swelling is painful and cause not known

You think your child needs to be seen, but the problem is not urgent

Contact Doctor During Office Hours

Large lump more than 1 inch (2.5 cm) and cause not known

Small lump lasts more than 7 days and cause not known

You have other questions or concerns

Self Care at Home

Small lump present 7 days or less and cause not known. Reason: probably due to insect bite not observed.

Breast bud - normal lump under the nipple

External occipital protuberance - normal lump on back of head

Mastoid process - normal lump behind each lower ear

Xiphoid process - normal lump at bottom of breastbone

Care Advice

Treatment for a Small Lump or Swelling

What You Should Know:

Most new swellings are due to insect bites. Mosquito bites account for 90% of them. Your child may not even know that he got bit.

Suspect an insect bite if there are bites on other parts of the body.

While most insect bites cause a small red bump, some are larger (like a hive).

This does not mean your child has an allergy or the bite is infected.

Here is some care advice that should help.

Cold Pack for Swelling:

Apply a cold pack or cold wet washcloth for 20 minutes.

Steroid Cream for Itching:

If the swelling is itchy, use 1% hydrocortisone cream (such as Cortaid). No prescription is needed.

Do this 3 times per day.

Allergy Medicine for Itching or Swelling:

For severe itch or swelling, give an allergy medicine by mouth. No prescription is needed.

Benadryl is best. Repeat every 6 hours as needed.

If you only have another allergy medicine at home (but not Benadryl), use that. Follow the package directions.

What to Expect:

Most insect bites itch or hurt for 1 or 2 days.

The swelling usually peaks in 2 days, but may last a week.

If the swelling becomes larger or doesn't go away, it needs to be examined.

Call Your Doctor If:

Swelling becomes very painful

Fever occurs

Swelling becomes large (over 1 inch or 2.5 cm)

Swelling lasts over 7 days

You think your child needs to be seen

Your child becomes worse

Lumps that are a Normal Part of the Body

Breast Buds - Normal Lump Under the Nipple:

Breast buds are normal, small disc-shaped rubbery lumps felt under the nipple.

Age. They normally occur in 8-12 year old girls and are the first sign of puberty. Sometimes, they are even normal in 7 year olds.

One Side. They sometimes start just on one side. Don't worry about that. Within 2 or 3 months, a breast bud will also appear on the other side.

Importance. The entire breast develops entirely from the breast bud, taking 2 or 3 years to completion.

Symptoms. Breast buds normally can be somewhat tender.

Caution: Never squeeze or massage breast buds. Reason: Can cause a serious infection.

Risks. None. Breast buds have no risk of turning into cancer.

Follow-up. You can have your child's doctor check the breast bud during the next regular office visit.

External Occipital Protuberance - Normal Lump on Back of Head:

The lump you feel at the base of the skull in back is normal. It is a bony part of the skull that sticks out and feels hard.

If you feel carefully, you will find one on yourself or other children.

This is not caused by any injury.

Mastoid Process - Normal Lump Behind the Ear:

The mastoid process is a bony lump you can feel behind the lower ear.

Muscles that turn the neck attach to the mastoid process.

The process is larger in men because of larger neck muscles.

The mastoid is filled with air cells that connect to the inner ear.

Xiphoid Process - Normal Lump at Bottom of Breastbone:

The small hard lump at the lower end of the sternum (breastbone) is normal. It is called the xiphoid process. You can feel it.

It is more prominent in babies and slender children. Sometimes, it's more visible when breathing in.

If you feel carefully, you will find one on yourself or other children.

It's made of cartilage, but turns to bone in adults.

Call Your Doctor If:

You have other questions or concerns

And remember, contact your doctor if your child develops any of the 'Call Your Doctor' symptoms.

Disclaimer: this health information is for educational purposes only. You, the reader, assume full responsibility for how you choose to use it.